Since last week, a whopping 134 earthquakes within three miles of that 4.6 tremor were recorded, USGS said.

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HIGH ALERT: Experts believe a magnitude 7 earthquake is 'inevitable' in California

The DEADLIEST earthquakes of all time

Earthquakes have struck terror into the heart of mankind since the dawn of time. These once inexplicable phenomena were interpreted by primitive civilisations as the anger of the gods. With death tolls of up to half a million people, it's not hard to see why. Warning: contains GRAPHIC IMAGES

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Messina, Italy, 1908, 7.1 on the Richter scale. Between 75,000 and 200,000 lives were lost

Of those earthquakes, only 17 were stronger than a 2.5 magnitude and six greater than 3.0, USGS said.

Ole Kaven, a USGS seismologist, said he expects more aftershocks in the coming weeks.

“This one has been a quite productive aftershock sequence,” said Kaven.

“We suspect there will be aftershocks in the 2 to 3 [magnitude] range for at least a few more weeks.”

There were no reports of injuries or significant damage as a result of the earthquake swarm.

Yet, a 4.6 tremor is at the "higher end of what we expect in terms of magnitude" for that area, Kaven said.

In the short term, this swarm has dramatically increased the chances of a colossal earthquake rattling the region, according to experts.

Scientists believe the US state is long overdue a magnitude 7 or greater earthquake by around 50 years.

Over the past 150 years, pressure has been building up along the San Andreas Fault that experts believe could unleash the next major earthquake.

Seismologist Lucy Jones, of the US Geological Survey, said the fault is the most likely of California’s 300 to produce a major earthquake.

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Managua, the capital city of Nicaragua in Central America is a hotpot of volcano and earthquake activity. Citizens were asked to take part in a drill to prepare for the eruption of two nearby volcanoes, or an earthquake measuring 7.4 on the Richter scale

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A boy takes part in a earthquake simulation exercise in Managua

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DEVASTATION: Thousands of people could die if a magnitude 7 earthquake struck California

“When we have a big San Andreas earthquake it’ll be felt in Las Vegas and in Arizona. It may be felt in the Bay Area,” she said.

The damage and death unleashed by an earthquake that size would be catastrophic, Jones said.

She estimates more than 1,800 people would die, around 300,000 homes would be destroyed and £160billion ($213billion) in damages would be incurred.